Known ranging devices include a Time-Of-Flight (TOF) type range image sensor (for example, see Patent Literature 1). In the ranging device disclosed in Patent Literature 1, a plurality of range sensors is disposed in a one-dimensional direction. Each range sensor includes a rectangular charge-generating region, a pair of transfer-electrodes, and a pair of charge-accumulating regions. The pair of transfer-electrodes are respectively provided along a pair of sides opposing each other in the charge-generating region. The pair of charge-accumulating regions respectively accumulate signal charges transferred from the transfer-electrodes.
In this ranging device, each transfer-electrode distributes charges, as the signal charges, generated in the charge-generating region into each charge-accumulating region in accordance with transfer-signals having different phases. The distributed signal charges are accumulated in each corresponding charge-accumulating region.
The signal charges accumulated in each charge-accumulating region are read out as outputs corresponding to a quantity of the accumulated charges. Based on a rate of these outputs, a distance to an object is calculated.